You probably want "mm-base.uci" which is in "Testing" in the respository.

That should should stop the missing library error if that's yur problem.

That's an old version of ffmpeg, but it works fine for most things. I did try to compile a new version over a year ago, but ran into too many dependancy problems. I can't remember if it was impossible or I just ran out of time.

This might convert a MPEG2 video to MPEG4, copy the audio without transcoding, and resize the video to 800x600, putting the result in the AVI container format. The result being testvid.mp4. EDIT: Though if using the AVI container, the output extension should be ".avi". ffmpeg can also guess the format you want to convert to based on the extension of the output filename, if a format isn't specified with the -acodec and -vcodec switches.

There a a huge number of options for ffmpeg. It can cut, join and combine video and audio files among many other things.

There are a few ffMPEG GUIs around, but I don't know if there are packages for any in the respository.